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| author | delphij <delphij@FreeBSD.org> | 2014-10-06 17:27:49 +0000 |
|---|---|---|
| committer | delphij <delphij@FreeBSD.org> | 2014-10-06 17:27:49 +0000 |
| commit | b754ead53081cb8550dd5712305e0d9c54b773cb (patch) | |
| tree | d337eee4cc9764071c92813c68b86c327a48232e /sys/cddl | |
| parent | dcccd3d8ca02684d9cc8a31ee368d2fa8a84c425 (diff) | |
| download | FreeBSD-src-b754ead53081cb8550dd5712305e0d9c54b773cb.zip FreeBSD-src-b754ead53081cb8550dd5712305e0d9c54b773cb.tar.gz | |
MFC r271532: MFV r271515:
Add a new tunable/sysctl, vfs.zfs.free_max_blocks, which can be used to
limit how many blocks can be free'ed before a new transaction group is
created. The default is no limit (infinite), but we should probably have
a lower default, e.g. 100,000.
With this limit, we can guard against the case where ZFS could run out of
memory when destroying large numbers of blocks in a single transaction
group, as the entire DDT needs to be brought into memory.
Illumos issue:
5138 add tunable for maximum number of blocks freed in one txg
Diffstat (limited to 'sys/cddl')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c index 5556af7..e75b1a5 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c @@ -99,6 +99,11 @@ SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RW, &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching"); enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; +/* max number of blocks to free in a single TXG */ +uint64_t zfs_free_max_blocks = UINT64_MAX; +SYSCTL_UQUAD(_vfs_zfs, OID_AUTO, free_max_blocks, CTLFLAG_RWTUN, + &zfs_free_max_blocks, 0, "Maximum number of blocks to free in one TXG"); + #define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ @@ -1350,6 +1355,9 @@ dsl_scan_free_should_pause(dsl_scan_t *scn) if (zfs_recover) return (B_FALSE); + if (scn->scn_visited_this_txg >= zfs_free_max_blocks) + return (B_TRUE); + elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && |
